Frankie Dettori's outgoing personality could make him a Celebrity Big Brother hit, but he also suffers from dark moods. Photograph: Julian Herbert/Action Images

Frankie Dettori will take the biggest gamble of his career on Thursday night when he enters the Celebrity Big Brother house for the latest series on Channel 5.

The programme's producers have refused to reveal the identities of the stars lined up to appear on the show but the Daily Telegraph reported on Wednesday night that friends of the 42-year-old jockey had confirmed he would be taking part.

The Italian is the second racing personality to appear on the programme following the ex-Channel 4 racing presenter John McCririck's appearance in 2005. The broadcaster's time in the house is chiefly remembered for a long sulk over not being allowed coke – the drink not the drug – and for his awful taste in underpants.

Dettori has been made second favourite at around 5-1 behind the X Factor star Rylan Clark to win the outright public vote and such is his outgoing personality that he could end up a winner in both senses, as he has work to do to redeem his reputation with the racing public too.

The rider is a mercurial character, though, and has dark moods – something he refers to as "the Mondays" – and there is also a chance that it might not turn out well for him. Some within the sport fear that, if it goes wrong, it could reflect badly on racing, Dettori being one of the few publicly recognisable characters involved in the game.

The fee for appearing on the programme is not disclosed but it is also being reported that part of Dettori's payment will go to the Peter O'Sullevan Trust, the Fortune Centre of Riding Therapy and the charity founded by the trainer Barney Curley, DAFA (Direct Aid For Africa).